Necrosis of the hand after extravasation of intravenously administered phenytoin.

Extravascular escape of intravenously administered phenytoin can result in serious local soft tissue complications. Injury can range from simple phlebitis to chemical cellulitis or, in extreme cases, frank tissue necrosis that necessitates amputation. The histopathologic findings include extensive necrosis and sloughing of epidermis, widespread necrosis of dermis, subcutaneous tissue, muscles and nerves, and extensive thrombotic occlusion of vessel lumens. Results of elastic tissue stains reveal that the thrombosed vessels are exclusively veins and venules. Vascular fibrinoid necrosis, leukocytoclasis, and true inflammatory vasculitis are not features. This is the first detailed report of the histopathologic alterations associated with this therapeutic misadventure.